Well, just to confirm what I thought I remembered: I tried again to set up bridging, and it is not possible using the method that works for wired ethernet. That is, I define a bridge br0 using the brctl command (as root of course) and then add interfaces to the bridge. I can add eth0 without difficulty, just as on other machines. But if I try to add the wireless interface wlan0, the command is rejected:
can't add wlan0 to bridge br0: Operation not supported I have used iptables (and earlier versions of the command, ipchains or ifwadm) to set up software firewalls before, and even to NAT ip addresses, but I've never seen a way to make it change a MAC address. Even if I had, I have no idea how to apply that to the output of the SIMH XQ device. Are you saying I should create a tun device or something similar to which XQ0 can be attached, and then re-route packets from that device to wlan0 by using iptables? I believe if IP were working, then DECNET can be routed or encapsulated over IP. But in this particular case, DECNET is inessential if I have working IP. The working IP tools and clients are sufficient. And I thought DECNET Plus didn't need to mess with MAC addresses anyway. Isn't it just DECNET IV that does that? On 11/17/12, TJ Merritt <[email protected]> wrote: > The TUN interface will get the packets injected into the system, but > will not get them bridged across the wireless network which uses the MAC > address for managing the wireless network. Since your MAC address for > the virtual interface is not the same as the mac address for the host, > reply packets over wireless will get dropped. The trick is to get the > packets to go out with the host's MAC address and replies routed back to > the virtual interface. > > VirtualBox does this by sending packets out with the original IP address > but the MAC address of the host, they then record the virtual interface > that the IP address came from, when the reply packet comes back, they > use the IP address to look up the virtual interface associated with that > IP address and route the packet to that interface. There are special > cases of course for things like broadcast, multicast, and IP addresses > that are shared between multiple VM's. VirtualBox does not currently > support IPv6 addresses though. This would also not help for DECnet. > This is effectively a layer 3 switching capability that works around the > lack of layer 2 switching in the wireless network. > > Another approach would be to setup NAT so that the NAT layer can take > care of the MAC address rewriting. It will also rewrite the IP address > though. If this is satisfactory, you there should be plenty of NAT > resources available to you on Mint such that no code writing is > required. > > Adding virutal networking support for wireless networks would be a major > undertaking for SimH, but if done, could eliminate most of the hiccups > with virtual networking over wireless networks. > > Of course, not of these issues occur over wired netowrks. > > -- TJ > > On Sat, 2012-11-17 at 15:24 -0500, Dan Gahlinger wrote: >> It works... >> use the TUN interface and the bridging, works just fine. >> >> >> Dan. >> >> >> > Date: Sat, 17 Nov 2012 14:14:24 -0600 >> > From: [email protected] >> > To: [email protected] >> > Subject: [Simh] VAX XQ and wireless networking >> > >> > Is this even possible? I have SIMH 3.9 on Linux Mint 12, running the >> > VAX with OpenVMS 7.3. It works great, except for networking. The >> > hardware is ASUS EeePC with Atheros AR5001 wireless network adapter >> > and Atheros L2 Fast Ethernet adapter. >> > >> > I have libpcap version 1.1.1 (which is also callable as version 0.8) >> > installed on Linux. The VAX module was compiled with networking >> > enabled. >> > >> > The configuration file has an "attach xq0 wlan0" or "attach xq0 >> eth0" >> > depending on which interface I'm trying to use. With the wired >> > ethernet (eth0) I am able to use both TCP/IP and DECNET Plus. With >> the >> > wireless (wlan0) neither one works. >> > >> > I've tried disabling the DECNET IV compatibility mode, which was >> > recommended in one source for wireless compatibility, and also tried >> > adding "set xq xx-yy-zz-aa-bb-cc" (with the actual MAC address of >> the >> > wireless adapter) to the configuration. The first did nothing I >> could >> > discern, and the second generated an error message during startup of >> > the SIMH module, saying that the MAC address was already in use and >> > could not be assigned. >> > >> > Obviously the workaround is to use a cabled connection when the VAX >> > emulator is needed, but this isn't very practical in most cases. Is >> > there any other possibility I've overlooked? >> > >> > I notice that this is a frequently found question when using Google >> to >> > look for answers, but I found no responses other than the two >> > solutions mentioned above. I suppose a different network card >> > emulation for VAX could make the wi-fi adapter look like a normal >> > ethernet interface, but apparently that hasn't been done yet and >> it's >> > probably beyond my very rudimentary C coding abilities. >> > _______________________________________________ >> > Simh mailing list >> > [email protected] >> > http://mailman.trailing-edge.com/mailman/listinfo/simh >> >> _______________________________________________ >> Simh mailing list >> [email protected] >> http://mailman.trailing-edge.com/mailman/listinfo/simh > > > _______________________________________________ Simh mailing list [email protected] http://mailman.trailing-edge.com/mailman/listinfo/simh
